Detecting incipient sensor faults in flight control systems

This paper develops a new approach to the design of optimal observer-based residual generators for detecting incipient faults in flight control systems. To reduce false and missed alarm rates in fault detection, a number of performance indices are introduced into the observer design. These indices are expressed in the frequency domain to take into account of the frequency distributions of faults, noise and modelling uncertainty. To solve the design problem, these performance indices are mixed together using different weighting factors as a single performance index. The genetic algorithm is thus used to search an optimal solution to minimize this design objective. The approach developed is applied to a flight control system example and simulation results show that incipient sensor faults can be detected reliably in the presence of modelling uncertainty